No. I often have this problem just with two instances open accidentally. I.e. left one minimized, forgot then opened it again.
If you're using Chrome then keep it in a pinned tab. (Right click on tab, "Pin Tab")
Or Firefox. Firefox will also send you to the open tab if you try to go to an URL you already went to, instead of opening a second instance of the same page.
Last write wins. Although tiddlywiki does detect the situation when file was changed on disk, there is not much you can do at this point. Before tiddlywiki I used to use pmwiki on a server and it has the ability to merge changes (via diff3). I miss that dearly in tiddlywiki.